Abstract: Described is an adhesive containing a polycarbodiimide resin having repeating units represented by the following formula:.paren open-st.R--N.dbd.C.dbd.N.paren close-st..sub.nwherein R is a divalent hydrocarbon group and n is an integer of 5 to 250, and also described is a flexible printed circuit board and a coverlay film fabricated using the above-described polycarbodiimide resin-containing adhesive.

Abstract: Described is an adhesive containing a polycarbodiimide resin having repeating units represented by the following formula:.paren open-st.R--N.dbd.C.dbd.N.paren close-st..sub.nwherein R is a divalent hydrocarbon group and n is an integer of 5 to 250, and also described is a flexible printed circuit board and a coverlay film fabricated using the above-described polycarbodiimide resin-containing adhesive.

Abstract: The method for preparing a crosslinked polycarbodiimide according to the present invention comprises reacting a polydicarbodiimide compound with a compound, which has in a molecule thereof two or more hydroxy or mercapto groups, in the presence of an alcoholate of an alkali metal or of an alkaline earth metal. The crosslinked polycarbodiimide obtained according to the method is excellent in heat resistance and mechanical properties.

Abstract: A hydroxy- or mercapto-bearing organic compound is caused to react with a polycarbodiimide compound in the presence of an alcoholate of an alkali metal or of an alkaline earth metal. The carbodiimide linkage in the polymer which results from the above-described reaction is crosslinked.

Abstract: A polycarbodiimide compound is reacted with an organic compound having at least two amino groups in the molecule. A polycarbodiimide compound is reacted with an amine compound having a silicon atom in the molecule. The carbodiimide bonds remained in the crosslinked material are further crosslinked. The crosslinked material is further heated/calcined to obtain an inorganic material having high heat resistance and strong toughness.

Abstract: This invention provides a process for the preparation of a polycarbodiimide solution wherein the polycarbodiimide is synthesized by heating an organic diisocyanate (e.g., 2,4-tolylene diisocyanate or 2,6-tolylene diisocyanate) in the presence of a carbodiimidation catlayst characterized in that a non-chlorinated aromatic hydrocarbon is used as the solvent and the resulting polycarbodiimide has a number average molecular weight from about 3,000 to about 10,000; wherein the synthesis is performed in the temperature range of from about 100.degree. to about 120.degree. C.

Abstract: This invention provides a process wherein a stable solution of polycarbodiimide with a number-average molecular-weight of 5,000 to 60,000 can be very easily prepared by using an organic diisocyanate (e.g., 2,4-tolylene diisocyanate or 2,6-tolylene diisocyanate) as starting material, a cyclic phosphine oxide as catalyst and a chlorinated aromatic compound as solvent and by controlling certain reaction conditions within the reaction temperature range of 110.degree. to 150.degree. C.